Overgeneral memory for public and autobiographical events in depression and schizophrenia

“I remember the attack”: a pilot study investigating flashbulb memory in individuals with schizophrenia

Flashbulb memories are autobiographical memories for important and emotional events, which have the particularity of being at the intersection of personal and public events. Autobiographical memory impairments are highly prevalent in schizophrenia, a psychiatric condition intrinsically linked to self-disorders. Thus, we aimed to evaluate flashbulb and event memory functioning in individuals with schizophrenia. Twenty-four individuals diagnosed with schizophrenia and 25 control participants were tested on a flashbulb memory questionnaire about the July 14th, 2016, Nice (France) terrorist attack, including questions on flashbulb and event memory, certainty, vividness, rehearsal, emotion, novelty, consequentiality, implication, and importance. Participants also underwent cognitive assessments. Analysis showed lower scores for both flashbulb and event memories in patients compared to control participants. Subjective ratings of the phenomenological characteristics of flashbulb memory were similar between the two groups overall. However, individuals with schizophrenia reported having higher levels of emotion when they first learned about the attack compared to the control group. Our results replicate findings of impaired autobiographical memory functioning in schizophrenia and extend these findings to public events. Our findings also indicate that flashbulb memories may lead to substantial contextual recall in schizophrenia patients and that collective memories, such as a terrorist attack, can have a profound emotional impact on patients.

Exploring the role of interoception in autobiographical memory recollection

The way we perceive signals coming from the inside of the body (i.e., interoception) may influence the processing of information related to the self. In this study, we investigated whether interoceptive sensibility may play a role in autobiographical memory processes. We evaluated 41 healthy participants with a modified version of the Autobiographical Memory Test, also assessing specificity, vividness, emotional valence, and intensity for autobiographical and public memories. Participants completed a self-report questionnaire measuring interoceptive sensibility. Results showed that autobiographical memories were recalled with higher specificity, vividness, and emotional intensity than public memories. Interestingly, we found that participants with (self-reported) high interoceptive sensibility recalled more positive events in the autobiographical compared to the public condition. Our findings provided new evidence on the selective role of physiological aspects of bodily self-awareness in autobiographical memory, suggesting that interoception is fundamental for supporting adaptive emotion regulation processes when recollecting engrams related to the self.

A review of autobiographical memory studies on patients with schizophrenia spectrum disorders

BACKGROUND

Patients suffering from schizophrenia spectrum disorders demonstrate various cognitive deficiencies, the most pertinent one being impairment in autobiographical memory. This paper reviews quantitative research investigating deficits in the content, and characteristics, of autobiographical memories in individuals with schizophrenia. It also examines if the method used to activate autobiographical memories influenced the results and which theoretical accounts were proposed to explain the defective recall of autobiographical memories in patients with schizophrenia.

METHODS

PsycINFO, Web of Science, and PubMed databases were searched for articles published between January 1998 and December 2018. Fifty-seven studies met the inclusion criteria. All studies implemented the generative retrieval strategy by inducing memories through cue words or pictures, the life-stage method, or open-ended retrieval method. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement guidelines were followed for this review.

RESULTS

Most studies reported that patients with schizophrenia retrieve less specific autobiographical memories when compared to a healthy control group, while only three studies indicated that both groups performed similarly on memory specificity. Patients with schizophrenia also exhibited earlier reminiscence bumps than those for healthy controls. The relationship between comorbid depression and autobiographical memory specificity appeared to be independent because patients' memory specificity improved through intervention, but their level of depression remained unchanged. The U-shaped retrieval pattern for memory specificity was not consistent. Both the connection between the history of attempted suicide and autobiographical memory specificity, and the relationship between psychotic symptoms and autobiographical memory specificity, remain inconclusive. Patients' memory specificity and coherence improved through cognitive training.

CONCLUSIONS

The overgeneral recall of autobiographical memory by patients with schizophrenia could be attributed to working memory, the disturbing concept of self, and the cuing method implemented. The earlier reminiscence bump for patients with schizophrenia may be explained by the premature closure of the identity formation process due to the emergence of psychotic symptoms during early adulthood. Protocol developed for this review was registered in PROSPERO (registration no: CRD42017062643).

Impaired contextual fear-conditioning in MAM rodent model of schizophrenia

The methylazoxymethanol acetate (MAM) rodent neurodevelopmental model of schizophrenia exhibits aberrant dopamine system activation attributed to hippocampal dysfunction. Context discrimination is a component of numerous behavioral and cognitive functions and relies on intact hippocampal processing. The present study explored context processing behaviors, along with dopamine system activation, during fear learning in the MAM model. Male offspring of dams treated with MAM (20mg/kg, i.p.) or saline on gestational day 17 were used for electrophysiological and behavioral experiments. Animals were tested on the immediate shock fear conditioning paradigm, with either different pre-conditioning contexts or varying amounts of context pre-exposure (0-10 sessions). Amphetamine-induced locomotor activity and dopamine neural activity was measured 1-week after fear conditioning. Saline, but not MAM animals, demonstrated enhanced fear responses following a single context pre-exposure in the conditioning context. One week following fear learning, saline rats with 2 or 7min of context pre-exposure prior to fear conditioning also demonstrated enhanced amphetamine-induced locomotor response relative to MAM animals. Dopamine neuron recordings showed fear learning-induced reductions in spontaneous dopamine neural activity in MAM rats that was further reduced by amphetamine. Apomorphine administration confirmed that reductions in dopamine neuron activity in MAM animals resulted from over excitation, or depolarization block. These data show a behavioral insensitivity to contextual stimuli in MAM rats that coincide with a less dynamic dopamine response after fear learning.

Autobiographical memory deficits in patients with depression follow a temporal distribution

Autobiographical memory deficits are known in depression. The temporal distribution thereof across periods of life has rarely been considered yet. Autobiographical memories for 5 life periods were investigated in 27 depressed in-patients and compared to 31 matched healthy controls using the Bielefelder Autobiographisches Gedächtnis Inventar. Depressed patients reported significantly less details in memories dating from childhood to 30 years, correlating with severity of depression. Memories from childhood and recent periods were less positive in depressed patients. Thus, we found a distinct pattern of autobiographical memory deficits in depressed patients. Possible etiological factors, however, need further investigations.

Mapping autobiographical memory in schizophrenia: Clinical implications

Increasing evidence suggests that impaired autobiographical memory (AM) mechanisms may be associated with the onset and maintenance of psychopathology. However, there is not yet a comprehensive review of the components of autobiographical memory in schizophrenic patients. The first aim of this review is a synthesis of evidence about the functioning of AM in schizophrenic patients. The main autobiographical elements reviewed in schizophrenic patients include the study of overgeneral memory (form); self-defining memories (contents); consciousness during the process of retrieval (awareness), and the abnormal early reminiscence bump (distribution). AM impairments have been involved in the clinical diagnosis and prognosis of other psychopathologies, especially depression. The second aim is to examine potential parallels between the mechanisms responsible for the onset and maintenance of disturbed AM in other clinical diagnosis and the mechanisms of disturbed autobiographical memory functioning in schizophrenic patients. Cognitive therapies for schizophrenic patients are increasingly demanded. The third aim is the suggestion of key elements for the adaptation of components of autobiographical recall in cognitive therapies for the treatment of symptoms and consequences of schizophrenia.

Schizophrenia Spectrum Disorders Show Reduced Specificity and Less Positive Events in Mental Time Travel

Mental time travel refers to the ability to recall past events and to imagine possible future events. Schizophrenia (SCZ) patients have problems in remembering specific personal experiences in the past and imagining what will happen in the future. This study aimed to examine episodic past and future thinking in SCZ spectrum disorders including SCZ patients and individuals with schizotypal personality disorder (SPD) proneness who are at risk for developing SCZ. Thirty-two SCZ patients, 30 SPD proneness individuals, and 33 healthy controls participated in the study. The Sentence Completion for Events from the Past Test (SCEPT) and the Sentence Completion for Events in the Future Test were used to measure past and future thinking abilities. Results showed that SCZ patients showed significantly reduced specificity in recalling past and imagining future events, they generated less proportion of specific and extended events compared to healthy controls. SPD proneness individuals only generated less extended events compared to healthy controls. The reduced specificity was mainly manifested in imagining future events. Both SCZ patients and SPD proneness individuals generated less positive events than controls. These results suggest that mental time travel impairments in SCZ spectrum disorders and have implications for understanding their cognitive and emotional deficits.

A Meta-Analysis of Autobiographical Memory Studies in Schizophrenia Spectrum Disorder

Meta-analyses and reviews on cognitive disorders in schizophrenia have shown that the most robust and common cognitive deficits are found in episodic memory and executive functions. More complex memory domains, such as autobiographical memory (AM), are also impaired in schizophrenia, but such impairments are reported less often despite their negative impact on patients' outcome. In contrast to episodic memory, assessed in laboratory tasks, memories of past personal events are much more complex and directly relate to the self. The meta-analysis included 20 studies, 571 patients with schizophrenia spectrum disorder, and 503 comparison subjects. It found moderate-to-large effect sizes with regard to the 3 parameters commonly used to assess AM: memory specificity (g = -0.97), richness of detail (g = -1.40), and conscious recollection (g = -0.62). These effect sizes were in the same range as those found in other memory domains in schizophrenia; for this reason, we propose that defective memories of personal past events should be regarded as a major cognitive impairment in this illness.

Memory impairment in chronic pain patients and the related neuropsychological mechanisms: a review

OBJECTIVE

This study provides a comprehensive review of the literature on memory impairment and the potential effective factors in patients with chronic pain.

METHODS

A literature search of databases PubMed, EMBASE, SpringerLink, and PsycINFO until September 2012 was conducted using the keywords ‘memory’ and ‘chronic pain’. The study emphasises on publications over the past 20 years.

RESULTS

Memory impairment in chronic pain patients is substantial, but the aspects of memory (e.g. working memory, long-term memory, and autobiographical memory) in chronic pain patients and the potentially related factors (e.g. age, level of education, pain conditions, emotion, neural network, and use of analgesics) are modest. Memory impairment is interpreted with the attention-narrowing hypothesis and the capacity-reduction hypothesis.

CONCLUSIONS

The currently available data and theory have explained memory impairment in chronic pain patients, but many controversies remain. Future research should focus on the subclinical characteristics of chronic pain, enlarging the sample size, and emphasise on the experimental intervention method and the cognitive neuroscience method.

Overgenerality memory style for past and future events and emotions related in bipolar disorder. What are the links with problem solving and interpersonal relationships?

This study investigated patients with Bipolar Disorder's abilities to generate specific past and future events in response to positive and negative cues words as well as emotional intensity related to these ones. The relationships between the number of generated specific events cognitive functioning, interpersonal problems and the ability to problem solving were investigated. Nineteen BD and nineteen healthy controls completed a French version of the AMT to evaluate the past and future events recall, in function of their valence, and emotions related. Furthermore, they completed the Optional Thinking Test, the Inventory of Interpersonal Problems and the neuropsychological measures. Compared to healthy controls, BD recollected (1) fewer specific past negative events and (2) fewer future specific positive and negative events furthermore, (3) they felt more emotional intensity related to future events. These results were explained in the light of theoretical models. Finally, specific past memories deficits in BD were linked with issues in problem solving but not with levels of distress arising from interpersonal problems. In view of AM functions in everyday life, all types of deficits should be taken into consideration, and AM remediation envisaged.

Abnormalities of autobiographical memory of patients with depressive disorders: a meta-analysis

BACKGROUND

Previous studies on the autobiographical memory (AM) of depressed patients had inconsistent findings. Various severities of depression in patients in these studies may lead to conflicting results. However, the differences in the procedure of the autobiographical memory tests (AMTs) may also influence the AM results.

OBJECTIVE

In this study, we analyse the results published so far to research the AM characteristics of patients with depressive disorders and identify moderators that affect the assessment results while using AMT in this field.

METHOD

A systematic search was conducted using following databases: MEDLINE, PubMed, ScienceDirect, Cnki, and Google Scholar, yielding 22 studies of patients with depressive disorders and autobiographical memory published between 1986 and 2010.

RESULTS

The results of meta-analysis showed that, compared with the control group, the patients with depressive disorders reported less specific AMs (g = -1.051) and more overgeneralized AMs (g = 1.115). The patients with depressive disorders also recalled more slowly (g = 0.400). The effect sizes of overgeneral memory could be predicted by the self-reported depression score of the depressed patients (B = -.329, p < .01). The mean effect sizes of AMT indices were affected by the AMT characteristics (i.e., number of cue word, max response time, prompting, presentation of cue word, taping, and so on).

CONCLUSIONS

Our results suggest that overgeneralization and response lag are the AM deficits in patients with depressive disorders. The parameters of AMT are important factors, which are related to the inconsistency in the assessment of AM in patients with depressive disorders. Some recommendations on AMT and programme research design are given for future research.

Are habitual overgeneral recollection and prospection maladaptive?

BACKGROUND AND OBJECTIVES

Individuals with depression exhibit difficulty retrieving specific memories and imagining specific future events when instructed to do so relative to non-clinical comparison groups. Instead of specific events, depressed individuals frequently retrieve or imagine "overgeneral" memories that span a long period of time or that denote a category of similar events. Recently, Raes, Hermans, Williams, and Eelen (2007) developed a sentence completion procedure (SCEPT) to assess the tendency to recall overgeneral autobiographical memories. They found that specificity on this measure was associated with depression and rumination. We aimed to replicate these findings and to examine the tendency to imagine overgeneral future events.

METHODS

We had 170 subjects complete past (SCEPT) and future-oriented (SCEFT) sentence completion tasks and measures of depression severity, PTSD severity, hopelessness, and repetitive negative thought.

RESULTS

Although specificities of past and future events were correlated, neither SCEPT nor SCEFT specificity was negatively associated with depression severity, posttraumatic stress symptoms, repetitive negative thought (RNT), or hopelessness.

LIMITATIONS

Our data are cross-sectional, preventing any determination of causality and limiting our assessment of whether specificity is associated with psychological distress following a stressful life event. In addition, we observed poor internal consistency for both the SCEPT and SCEFT.

CONCLUSIONS

These findings fail to support the hypothesis that overgeneral memory and prospection on these tasks are associated with psychological distress.

True and false autobiographical memories in schizophrenia: preliminary results of a diary study

The frequency of true and false autobiographical memories and associated states of conscious awareness, i.e., conscious recollection and simply knowing, as well as the respective roles of affective and cognitive processes in autobiographical memory construction, were assessed in eight patients with schizophrenia and eight control participants. A diary study methodology was used in combination with the Remember/Know procedure. The results showed a higher frequency of Know responses associated with the retrieval of both true and false memories in patients than in control participants. Whereas control participants rated higher at retrieval than at encoding the distinctiveness and personal importance of events, as well as the extent to which events furthered current personal plans, patients exhibited an opposite pattern of ratings, with ratings being lower at retrieval than at encoding. These preliminary results show a high frequency of simply knowing associated with the retrieval of true and false autobiographical memories in patients with schizophrenia and provide evidence for the interest of the diary study methodology for studying autobiographical memory in schizophrenia.

Functional brain imaging in 14 patients with dissociative amnesia reveals right inferolateral prefrontal hypometabolism

Dissociative amnesia is a condition usually characterized by severely impaired retrograde memory functioning in the absence of structural brain damage. Recent case studies nevertheless found functional brain changes in patients suffering from autobiographical-episodic memory loss in the cause of dissociative amnesia. Functional changes were demonstrated in both resting state and memory retrieval conditions. In addition, some but not all cases also showed other neuropsychological impairments beyond retrograde memory deficits. However, there is no group study available that examined potential functional brain abnormalities and accompanying neuropsychological deteriorations in larger samples of patients with dissociative retrograde amnesia. We report functional imaging and neuropsychological data acquired in 14 patients with dissociative amnesia following stressful or traumatic events. All patients suffered from autobiographical memory loss. In addition, approximately half of the patients had deficits in anterograde memory and executive functioning. Accompanying functional brain changes were measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET). Regional glucose utilization of the patients was compared with that of 19 healthy subjects, matched for age and gender. We found significantly decreased glucose utilization in the right inferolateral prefrontal cortex in the patients. Hypometabolism in this brain region, known to be involved in retrieval of autobiographical memories and self-referential processing, may be a functional brain correlate of dissociative amnesia.